1. Technical Field
The present invention relates to a photoelectric encoder which is used in a linear encoder etc.
2. Related Art
Photoelectric encoders are used for precise measurements of linear displacements etc. Among photoelectric encoders, a 2-phase detection type photoelectric encoder is widely known which detects light reception quantities of two light beams diffracted by a scale (refer to FIG. 5 of Patent document 1). However, in general, scales are made of an emulsion. The optical characteristics of the scale are varied due to a temperature or humidity variation, as a result of which the measurement accuracy of the photoelectric encoder is lowered.